Removable computer display interface

ABSTRACT

A portable computer is configured to accept removable modular display panels of different types that plug into a structure hinged to the body of the computer. Each display panel has a sliding engagement means fixed along a lower edge, and the hinged structure has a mating sliding engagement means along an upper edge and parallel to the axis of the hinge, allowing a display panel to engage and disengage in the direction of the axis of the hinge. In an embodiment of the invention, display modules adaptable to the computer have a code stored in a memory device that is accessible on start-up by the computer, to identify and load a display driver routine capable of driving the display module assembled to the computer.

CROSS REFERENCE TO RELATED DOCUMENTS

This application is a continuation of Ser. No. 08/968,384 filed Nov. 12,1997 now U.S. Pat. No. 6,300,921 which is a continuation of Ser. No.08/562,835 filed Nov. 27, 1995 now abandoned, which is a divisional ofSer. No. 08/097,768, Jul. 26, 1993 now U.S. Pat. No. 5,546,098 which isa divisional of Ser. No. 07/918,966 filed Jul. 27, 1992 now U.S. Pat.No. 5,262,759, and disclosed on May 12, 1992 in Document Disclosure#309810.

FIELD OF THE INVENTION

This invention is in the field of architecture of portable computers,and pertains in particular to apparatus and methods of interfacingremovable physical displays to portable computers.

BACKGROUND OF THE INVENTION

The marketplace for portable computers, such as notebook and laptopcomputers, is one of the faster growing sectors of the computerindustry. There are many challenges in developing and designingcomputers of this sort, many of which are a result of need for lightweight, strength, and longevity of portable power sources.

Another area of innovation in the development of portable computers isdriven by the facts of use of portable computers as compared tostationary models. Portable computers have to operate under a variety ofconditions. For example, while a stationary model, such as a desktopcomputer, is typically used at a single location under relativelyconstant lighting conditions, a portable computer must be usable under avariety of lighting conditions in both indoor and outdoor situations. Insome situations it is even preferable to have a display that is usablein bright sunlight.

There are several different types of computer displays, and many newtypes being developed, all of which are what are called in the art “flatpanel” displays. Flat panel displays are necessary, because thewell-known CRT displays are much too bulky and vulnerable to be usedextensively for portable applications.

Among the many different types are Transflective displays, which havelow back light and low power consumption; standard monochromepaper-white displays, which are back-lit and exhibit moderate powerconsumption; and passive color displays, also known as super-twistnematic (STN), which have very good visibility and color, but exhibithigher power consumption.

There are seen to be, then, many issues one must consider when choosinga display, such as visibility under different ambient conditions, coloravailability and range, power consumption, and more. And in the currentstate-of-the-art, choosing the display is akin to choosing the computer,because most computers are not provided with a range of choices indisplay.

What is clearly needed is a portable computer with a physical interfacefor attaching and detaching a display panel, and a means of recognizingon power-up the specific display attached.

SUMMARY OF THE INVENTION

In a preferred embodiment of the invention a computer system is providedhaving a body structure that houses and supports computing elements,memory elements and input elements. The display for the system isprovided as a removable flat panel display module which has physical andelectrical joining elements for attaching to the body structure of thecomputer. The attachment is made to a mounting structure that is hingedto the body structure along a pivot axis, and the mounting structure hascorresponding physical and electrical joining elements to engage thoseprovided on the display module. The physical and electrical joiningelements are aligned to join and disjoin by motion in the direction ofthe pivot axis, which provides for secure attachment in the event a userlifts the computer by the display module.

In a preferred embodiment the physical mating elements comprise engagingrails with an engaging direction parallel to the pivot axis of themounting structure, and a snap-in structure having a matching slot and adisengagement pushbutton comprising a releasable detent mechanism. Theelectrical connection is made in this preferred embodiment by amulti-pin connector engaging and disengaging in the same direction asthe engagement rails.

Also in a preferred embodiment, modular displays for use with a computerconfigured to accept them have a code stored in a memory device, such asan EEPROM, for identifying the type of display, which is accessed by thecomputer memory and matched with a compatible display driver routine foroperating the display, which the computer then uses. Newly developeddisplays may then be used with computers previously manufactured andsold, by updating the computer BIOS and providing suitable driveroutines for such newly developed displays.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a portable computer according to theinvention with a removable modular display.

FIG. 2 is an elevation view of a modular display according to anembodiment of the invention, assembled to a mounting structure.

FIG. 3A is a view of the same components as shown in FIG. 2, but withthe modular display disjoined from the mounting structure.

FIG. 3B is a cross-section view through guide and engaging taken alongsection line 3B—3B of FIG. 2.

FIG. 3C is an elevation view of a latching mechanism employed in anembodiment of the invention.

FIG. 4 is a block diagram depicting an arrangement of elements of acomputer according to an embodiment of the invention, used forinitializing the computer to operate the modular display.

FIG. 5 is a block diagram of elements of a portable computer connectedto the elements of FIG. 4.

FIG. 6 is a logic flow diagram depicting steps of a method according toan embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is an isometric view of a notebook computer 11 with a removable,interchangeable display module 13 according to an embodiment of thepresent invention, allowing a variety of different types of displaymodules to be used with the same computer apparatus simply by removingone display module and substituting another. Notebook 11 also comprisesa keyboard 15 and a body portion 19. Display module 13 is shown in the“open” position, but may be rotated “closed” over the keyboard, where itmay be secured by conventional latching mechanisms.

In the embodiment shown in FIG. 1, display module 13 is configured toattach to a hinged mounting structure 17, having an “L” shape, whichremains with the computer when display module 13 is removed. The hingesbetween body portion 19 and mounting structure 17 are not seen in FIG.1, and may be accomplished in a number of conventional ways. In apreferred embodiment, the hinge mechanisms are pre-loaded to providesufficient friction to allow the display, if released at any partiallyopen position, to remain in that position.

FIG. 2 is a face-on view of the notebook computer in the direction ofarrow 21 of FIG. 1, showing more detail of the unique mounting ofdisplay module 13 to mounting structure 17 according to the presentembodiment of the invention. The unique mounting configuration providesfor display module 13 to approach and engage mounting structure 17 fromone side, in this case from the left, and to be removed also from theside, in the direction of arrow 23. FIG. 2A shows the display modulefully engaged.

FIG. 3A is a view of the notebook computer from the same vantage as inFIG. 2, but showing the display module fully disengaged from mountingstructure 17. In this embodiment there are three sets of linearlyengaging guides for guiding the display module into engagement, and forproviding structural rigidity when engaged. Guides 25 and 26 are oneset, guides 27 and 28 another set, and guides 29 and 30 a third set.Three sets have been found to be convenient. There could be one, two, ormore than three sets of guides in other embodiments.

FIG. 3B is a section taken through the engaging guide set comprisingguides 25 and 26 to better illustrate the details of engagement. In thisembodiment guide 25 has a T-shape, and guide 26 has a C-shape, such thatthe T-shape of guide 25 fits snugly within the C-shape of guide 26. Theengaging shapes of the other guide sets follow the same detail as theset shown.

Although not shown in the Figs. provided, the leading end of T-shapedguides are tapered for easy entry into the C-shaped guides. Also, thereis no necessity for one sort to be attached to the display module andthe other to the mounting structure.

Mounting structure 17 has a vertical portion 18 at one end, and displaymodule 13 has a cut-out area 31 of the same shape and size as verticalportion 18, so when the display module is fully engaged with mountingstructure 17 the two form a rectangular assembly. A snap-in structure 32fixedly attached to display module 13 extends into cut-out area 31, andaligns with and engages an engagement slot 33 in vertical portion 18 ofmounting structure 17 when the display module is fully engaged.

FIG. 3C shows additional detail of snap-in structure 32 and engagementslot 33. Structure 32 is injection molded plastic in the embodimentshown, and includes a cantilevered spring-lever 34 with a snap-inshoulder 35. Slot 33 has a shoulder 36 which engages shoulder 35 onstructure 32 when fully assembled, firmly locking display module 13 intostructure 17. A spring-loaded button 37 is configured to deflectcantilever spring 34 when the button is depressed, allowing disjoiningof the display module and the mounting structure.

There is additionally a connector 39 (FIG. 2) with a male (39′) and afemale (39″) part (FIG. 3A), for communication, power, and controlsignals between the computer and display module 13.

To remove a display from the computer, one depresses button 37 andslides the display to the side (direction of arrow 23), disengagingsnap-in structure 32 and connector 39, while at the same timedisengaging the three sets of linearly operating guides mounted acrossthe length of structure 17 and the display module When the linearlyoperating guides are disengaged, one may lift the display module awayfrom the computer. To engage the same or another display module, onesets the module in alignment on structure 17 with the matched linearguides adjacent, then slides the module in the direction of arrow 23 toaccomplish engagement. The purpose of having plural sets of engagingguides is to minimize the distance one must move the display module toone side when engaging ad disengaging.

The particular arrangement shown in FIGS. 2, 3A, 3B, and 3C has provento be advantageous, although there are other arrangements also useful.One could, for example, use round pins aligned with bores to accomplishguiding and engaging. In the embodiment shown the height of portion 18of structure 17 is about 6 cm., but could extend for the full height ofmodule 13.

A distinct advantage of the sideways engagement and disengagement forthe display module lies in the fact that the engaging guides, such asguides 25 and 26, may be easily moved in the engagement direction, butare extremely difficult to separate at a right angle to the engagingdirection. The same is true for other engaging devices that might beused, such as pins as mentioned above. One may pick the assembly up bythe display module and carry it that way, because the forces from doingso will be at a right angle to the length of the engagement elements,instead of in line with the direction of disengagement. This is aparticular advantage for the notebook computer.

In the embodiment shown power and control connection is made from thecomputer to display module 13 through the multi-pin electrical connector39 (FIG. 2), shown as male part 39′ and female part 39″ in FIG. 3. Inthe present embodiment there are 40 pins in the connector, although insome other embodiments there might be more or fewer.

As described above, the removable nature of the display module makes itpossible to provide a variety of display modules to be used with asingle notebook computer. A user may then be offered a number ofpurchase options. One might desire, for example, to have two displaymodules, one capable of providing optimum performance under officeconditions, and another for outdoor use. The replaceable nature of thedisplay module also allows a user to update to higher performance (andperhaps more expensive) displays at a time after purchase. One also hasthe option of interfacing displays to the computer that may be developedat a later time.

An additional feature of the invention is an ability on power-up toascertain the nature of the display module and to provide the correctpower and control signals for the assembled module.

FIG. 4 is a block diagram showing the connection of power and controlelements in an embodiment of the invention. In this embodiment a displayboard 41 is incorporated into the computer with connection to the systemparallel bus 52, and having output to 40-pin connector 39 along path 40.Display module 13 comprises a flat panel display 43, which, in thisembodiment is a component obtained from one of several suppliers of flatpanel displays. As is typical in the industry, display 43 comprises“tabs” such as tab 45, which incorporate logic for converting datacommunication to on-off status for crossed traces that activate bits inthe bit-array of the display. In this embodiment the display emulates to640 column by 480 line standard of VGA displays. Displays in the artcome complete with wiring connections and signal requirements, includingdata format and so forth, so the computer manufacturer using the displaymay provide the correct operating signals.

The display module also comprises circuitry 47, including an adjustableDC/DC converter 49 and a EEPROM memory device 51 for storing a codeassociated with the type display with which the EEPROM is associated.Circuitry 47 is connected to connector 39 by path 42, and providesoutput to display 43 via path 44. The DC/DC converter receives a powertrace through the connector, and provides output for contrast voltageand backlighting, which may be adjusted via user signals. This output ispart of the signals on path 44 to display 43. In one variation, thecontrast and brightness are adjustable by keystroke combinations, and ina more preferred mode, when a pointing device (such as a mouse) is used,the contrast and brightness may be adjusted by movement of the pointingdevice. In both variations, the adjustments are software controlled.There may also be input devices, such as familiar slide switches, on thedisplay module to make such adjustments.

In the present embodiment EEPROM 51 is programmed with a unique identitycode for the specific type of module. Each type of module offered forthe computer has a specific identity code. On initializing, the systemBIOS queries the display to ascertain the module type, and loads thecorrect routines to operate that module. For the situation where a newtype or improved display module is introduced, a simple BIOS upgradeallows previously manufactured computers to use the new display module.

Typically communication to the display module to control the bit-map ofthe display is by 8-bit serial data flow. The protocol for the serialcommunication, however, is not always the same from manufacturer tomanufacturer and for different display types. Hence the EEPROM code foridentity, which the computer system uses as a pointer to driver routinesto match the particular requirement of the display module. On power-up,as indicated above, the BIOS queries the display module and loads thecorrect display driver routines.

As a further aid in understanding the circuitry for the presentembodiment of the invention, Table I is provided with the present pinnumber assignments related to signal identification.

TABLE I Pin Assignments No. Pin Description 1 VCC Power to display logic2 VSS Ground to display logic 3 VEN Unused 4 VEP Unused 5 SDE Serial I/Oto EEPROM 6 SD1 Serial I/O to EEPROM 7 SD2 Serial I/O to EEPROM 8 CF1Contrast control (analog) 9 CF2 Brightness control (analog) 10 CF3Unused 11 CF4 Unused 12 DEN Display enable 13 FCL Frame clock 14 PCLPixel clock 15 RCL Row clock 16 ACL Modulation 17 UD0 Upper display data0 18 UD1 Upper display data 1 19 UD2 Upper display data 2 20 UD3 Upperdisplay data 3 21 UD4 Upper display data 4 22 UD5 Upper display data 523 UD6 Upper display data 6 24 UD7 Upper display data 7 25 LD0 Lowerdisplay data 0 26 LD1 Lower display data 1 27 LD2 Lower display data 228 LD3 Lower display data 3 29 LD4 Lower display data 4 30 LD5 Lowerdisplay data 5 31 LD6 Lower display data 6 32 LD7 Lower display data 733 RB Raw battery plus 34 RB Raw battery plus 35 RB Raw battery plus 36RB Raw battery plus 37 RBGND Raw battery ground 38 RBGND Raw batteryground 39 RBGND Raw battery ground 40 RBGND Raw battery ground

In this particular instance, there are two bit streams, one for an upperdisplay, and the other for a lower display, which are not separatedisplays at all, but upper and lower segments of the one display, drivenin parallel to avoid flicker. The 40-pin arrangement has proven to alsobe sufficient to drive color displays, which have, generally speaking,three times the dots in the display map as do monochrome displays.

There are many changes that may be made in the embodiments of theinvention described above without departing from the spirit and scope ofthe invention. For example, there are several ways the circuitry mightbe arranged to accomplish the task of querying the EEPROM in the displaymodule to determine the display type and drive requirements. Likewise, aEEPROM is convenient for storing the identity code at the displaymodule, but is not the only memory device that might be used. There arealso a number of alternative arrangements of elements to allow displaymodules to engage from one side, as described above. There are similarlymany other alterations that may be made without departing from thespirit and scope of the invention.

What is claimed is:
 1. A general-purpose computer comprising: a computerbody structure that houses and supports circuitry of said computer, saidcomputer body structure including a mounting structure that guides andengages a removable flat panel display for attachment to said computerbody structure; a removable flat-panel display having a display screenand an engagement apparatus that is guided and engaged by said mountingstructure so as to attach said flat panel display to said computer bodystructure; and mating electrical connectors on said flat panel displayand said computer body structure that, when connected, provide displaycontrol signals to said flat panel display from said circuitry housed bysaid computer body structure, wherein said mounting structure includes ahorizontal portion pivotally attached to said computer body structurealong a pivot axis and a slidable engagement apparatus mounted to thehorizontal portion that engages a corresponding slidable engagementapparatus of said engagement apparatus of said flat panel display in anengagement direction that is substantially parallel to the pivot axis,said mounting structure receiving and holding said flat panel display asa hinged unit closable over said computer body structure and openable toprovide access to said display screen.
 2. A computer as in claim 1,wherein said mounting structure includes one of round pins and alignedbores that engages said engagement apparatus of said flat panel display,said engagement apparatus including the other one of said round pins andaligned bores, whereby when said round pins and aligned bores areengaged, said mounting structure receives and holds said flat paneldisplay as a hinged unit closable over said computer body structure andopenable to provide access to said display screen.
 3. A computer as inclaim 1, wherein said mating electrical connectors comprise a firstportion of a multi-pin electrical connector mounted in an edge of saidflat panel display and a second portion of said multi-pin electricalconnector mounted in a portion of said mounting structure so as toengage said first portion when said flat panel display is guided intoposition and engaged by said mounting structure.
 4. A computer as inclaim 1, wherein said mounting structure includes one of a snap-inflange and an engagement slot and said engagement apparatus of said flatpanel display includes the other of said snap-in flange and saidengagement slot, said snap-in flange and engagement slot beingconfigured to engage and snap together as said flat panel display andsaid mounting structure fully engage, thereby holding said flat paneldisplay firmly in engagement with said mounting structure of saidcomputer body structure.
 5. A computer as in claim 4, further comprisinga release button that releases said snap-in flange from said engagementslot so as to release said flat panel display from said mountingstructure for removal.
 6. A computer as in claim 1, wherein said flatpanel display includes a non-volatile memory device containing a uniqueidentity code unique to the specific type of flat panel display and saidcircuitry of said computer provides data and command signals to the flatpanel display through said mating electrical connectors, said commandsignals including a command to return a code stored in said non-volatilememory of said flat panel display, said circuitry further selecting adriver routine associated with the code stored in the non-volatilememory for operation of said flat panel display.
 7. A computer as inclaim 1, wherein said engagement apparatus mounted to the horizontalportion comprises at least one engagement rail configured to engage acorresponding rail in said counterpart engagement apparatus of said flatpanel display.
 8. A flat panel display module for a computer,comprising: a display screen on a side of said display module thatdisplays output of said computer; an engagement apparatus on at leastone edge of said display module that joins said display module to saidcomputer; and an electrical connector on a side of said display modulethat electrically connects said display module to said computer, whereinsaid engagement apparatus is configured to engage a counterpartengagement apparatus on said computer whereby said display screen isattached to said computer so as to pivot from an open position forviewing to a closed position over a body structure of the computer, andwherein said engagement apparatus of said display module includes aslidable engagement apparatus and said counterpart engagement apparatusof said computer includes a mounting structure that includes ahorizontal portion pivotally attached to the computer body structure ofsaid computer along a pivot axis and a slidable engagement apparatusmounted to the horizontal portion that engages said slidable engagementapparatus of said flat panel display module in an engagement directionthat is substantially parallel to the pivot axis, said respectiveslidable engagement apparatuses receiving and holding said flat paneldisplay module as a hinged unit closable over said computer bodystructure of said computer and openable to provide access to saiddisplay screen.
 9. A display module as in claim 8, wherein saidengagement apparatus of said display module includes one of round pinsand aligned bores that engages said counterpart engagement apparatus ofsaid computer including the other one of said round pins and alignedbores, whereby when said round pins and aligned bores are engaged, saidrespective engagement apparatuses receive and hold said flat paneldisplay module as a hinged unit closable over said computer bodystructure of said computer and openable to provide access to saiddisplay screen.
 10. A display module as in claim 8, wherein saidelectrical connector comprises a first portion of a multi-pin electricalconnector mounted in an edge of said flat panel display, said electricalconnector cooperating with an electrical connector on said computer bodystructure comprising a second portion of said multi-pin electricalconnector, said first and second portions engaging when said flat paneldisplay module is guided into position and engaged by said engagementapparatus and counterpart engagement apparatus.
 11. A display module asin claim 8, wherein said counterpart engagement apparatus of saidcomputer includes one of a snap-in flange and an engagement slot andsaid engagement apparatus of said flat panel display module includes theother of said snap-in flange and said engagement slot, said snap-inflange and engagement slot being configured to engage and snap togetheras said engagement apparatus of said flat panel display module and saidcounterpart engagement apparatus fully engage, thereby holding said flatpanel display firmly in engagement with said computer body structure.12. A display module as in claim 8, wherein said engagement apparatus ofsaid display module comprises at least one engagement rail configured toengage a corresponding rail in said counterpart engagement apparatus ofsaid computer.
 13. A display module as in claim 8, further comprising anon-volatile memory device containing a unique identity code unique tothe specific type of flat panel display module and circuitry responsiveto data and command signals from the computer to return the uniqueidentity code stored in said non-volatile memory.
 14. A general-purposecomputer comprising: a computer body structure that houses and supportscircuitry of said computer, said computer body structure including amounting structure that guides and engages a removable flat paneldisplay for attachment to said computer body structure; and anelectrical connector on said computer body structure that, whenconnected to a mating electrical connector on said removable flat paneldisplay, provides display control signals to said flat panel displayfrom said circuitry housed by said computer body structure, wherein saidmounting structure includes a horizontal portion pivotally attached tosaid computer body structure along a pivot axis and a slidableengagement apparatus mounted to the horizontal portion that engages acorresponding slidable engagement apparatus of said removable flat paneldisplay in an engagement direction that is substantially parallel to thepivot axis, said mounting structure receiving and holding said removableflat panel display as a hinged unit closable over said computer bodystructure and openable to provide access to a display screen of saidremovable flat panel display.
 15. A computer as in claim 14, whereinsaid mounting structure includes one of round pins and aligned boresthat engages a counterpart engagement apparatus of said removable flatpanel display, whereby when said round pins and aligned bores of saidmounting structure and counterpart engagement apparatus are engaged,said mounting structure receives and holds said removable flat paneldisplay as a hinged unit closable over said computer body structure andopenable to provide access to a display screen of said removable flatpanel display.
 16. A computer as in claim 14, wherein said electricalconnector comprises a first portion of a multi-pin electrical connectormounted in said mounting structure, said electrical connectorcooperating with an electrical connector on said removable flat paneldisplay comprising a second portion of said multi-pin electricalconnector, said first and second portions engaging when said removableflat panel display is guided into position and engaged by said mountingstructure.
 17. A computer as in claim 14, wherein said mountingstructure includes one of a snap-in flange and an engagement slot and anengagement apparatus of said removable flat panel display includes theother of said snap-in flange and said engagement slot, said snap-inflange and engagement slot being configured to engage and snap togetheras said removable flat panel display and said mounting structure fullyengage, thereby holding said removable flat panel display firmly inengagement with said mounting structure of said computer body structure.18. A computer as in claim 17, further comprising a release button thatreleases said snap-in flange from said engagement slot so as to releasesaid removable flat panel display from said mounting structure forremoval.
 19. A computer as in claim 14, wherein said circuitry of saidcomputer requests from a connected removable flat panel display a uniqueidentity code unique to the specific type of removable flat paneldisplay and provides data and command signals to the removable flatpanel display through said electrical connector, said circuitry furtherselecting a driver routine associated with the code stored in thenon-volatile memory for operation of said removable flat panel display.20. A computer as in claim 14, wherein said engagement apparatus mountedto the horizontal portion comprises at least one engagement railconfigured to engage a corresponding rail in said counterpart engagementapparatus of said flat panel display.